644420298 has 8 divisors (see below), whose sum is σ = 1288840608. Its totient is φ = 214806764.

The previous prime is 644420297. The next prime is 644420303. The reversal of 644420298 is 892024446.

It is a sphenic number, since it is the product of 3 distinct primes.

644420298 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (644420291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53701686 + ... + 53701697.

It is an arithmetic number, because the mean of its divisors is an integer number (161105076).

Almost surely, 2^644420298 is an apocalyptic number.

644420298 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644420298 is a wasteful number, since it uses less digits than its factorization.

644420298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107403388.

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 644420298 is about 25385.4347609018. The cubic root of 644420298 is about 863.7533348284.

The spelling of 644420298 in words is "six hundred forty-four million, four hundred twenty thousand, two hundred ninety-eight".